【模板】求星期（已知年月日）

int getweek(int y,int m,int d)
{
    int x;
    if(m==1||m==2)
        m+=12,y--;
    if(y<1752||y==1752&&m<9||y==1752&&m==9&&d<3)
        x=(d+2*m+3*(m+1)/5+y+y/4+5)%7;
    else x=(d+2*m+3*(m+1)/5+y+y/4-y/100+y/400)%7;
    return x+1;
}